401(k) plans are a great way to accumulate wealth for retirement. Although 401(k) accounts often are used for long-term investing, participants can take out loans from their 401(k) accounts if needed. Shane McDougald, CFP® — a wealth advisor and 401(k) specialist — explains key rules for 401(k) loans, as well as for withdrawals while still working for the company that offers the 401(k) plan.